nickandanna ~
I didn't think I'd be back so soon, but I picked up this bit of information that may assist you in your research. It occured when I switched gears to "Aztec" instead of "Mayan." (Both are considered Pre-Columbian).
However ...
Mayan Time Period = circa 2000 BC to 25 AD
Aztec Time Period = circa 1200 AD to 1500 AD
And that's when I discovered a unique difference between the two. The majority of the Mayan figures seem to have the "Hands on the knees" motif. Whereas the Aztec figures seem to have "The Hands on the chest" motif. I'm sure there is some explaination for this, but I don't have a clue what it is. But if there is something to it, it suggest that your figure "might" be Mayan, and the older of the two. I suspect that the Spanish coquistadores/explorers grabbed anything and everything they could get their hands on, both Mayan and Aztec. And then sped away with their "treasures" on their ships!
Mayan Wikipedia link :
http://en.wikipedia.org/wiki/Maya_civilization
Aztec Wikipedia link :
http://en.wikipedia.org/wiki/Aztec
Here's a good example of an Aztec figure, with a reference about the folded arms in the following description ...
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AN AZTEC STONE FIGURE
Sold For $26,400.00
AN AZTEC STONE FIGURE, POSTCLASSIC, CA. A.D. 1200-1521
MEASUREMENTS
Height 30in. 76.2cm
DESCRIPTION
Poised in a reverential posture with arms crossed on the chest, a small concavity and groove extending up the neck, the face with rounded eyes and mouth open as if chanting, wearing a simple loincloth knotted in front and wrapped around the waist, supported on a small rectangular platform; in gray basalt.